Technical Field
The present invention relates to a method of providing connectivity to a vehicle.
Description of Related Art
With the increased portability of computers, and the increasing sophistication of mobile devices such as mobile telephones and palmtop computers, there is a growing demand for connectivity while on the move allowing, for example, connection with other devices, and the Internet. One response to this demand is based upon devices having built-in long-range telecommunications capabilities, such as devices which make use of mobile telephone networks. While such solutions can be effective, they typically suffer from problems of low bandwidth and incomplete geographic coverage. The problem of low bandwidth is a particular issue when a user wishes to access content comprising a large quantity of data (for example video content). The problem of incomplete geographic coverage is particularly problematic when a user is moving, given that data communication may be interrupted when a signal is lost (for example when a train enters a tunnel).
An alternative method of providing data connectivity to mobile devices is based upon the use of access points. Such access points may be provided, for example, in public buildings such as libraries and cafes, and can be accessed by mobile computing devices which are located within a predetermined range of the access point. One common technology used to allow mobile computing devices to connect to such access points is specified by IEEE standard 802.11, and is commonly referred to as WiFi. The use of access points in this way is advantageous in that it allows higher bandwidth connections to be established.
The limitations of systems based upon the connection of mobile devices to mobile telephone networks has led to the proposal that public transport vehicles, such as trains or buses, may be beneficially provided with wireless access points, such that mobile computing devices used by passengers traveling in the vehicle can be provided with data connectivity.
More power is available on the vehicle than on a mobile computing device, meaning that systems fitted to vehicles can generally support larger, higher gain antennas than those that are generally installed in portable user devices such as mobile telephones. Furthermore, greater computational power can be used in signal processing in a device associated with a vehicle given that there is room for larger, more powerful processing devices.
Different types of communication links can be used to provide data communication to a vehicle, separately or together, appropriate to the locations through which the vehicle travels. Furthermore, if a vehicle's route is known, the communication links can be managed to provide a higher level of service with greater bandwidth, lower latencies, and fewer losses of connection than if the communications were made directly to individual users using a mobile telephone network. It follows that the provision of a wireless access point on board a vehicle has considerable advantages. Such provision does, however, bring challenges.
It is known for vehicles to connect to base stations along a known route, for example alongside a train track. The base stations may be placed specifically for vehicles travelling along that route, or may be base stations of mobile network operators. It is further known for the vehicle to connect, via the connected base stations, to a home server. The home server may be connected to the Internet via standard means, for example via cable or via a digital subscriber line (DSL). A communication control unit is placed on the vehicle. As the vehicle travels along the route, the communication control unit wirelessly connects to a particular base station. In this way, the communication control unit can connect to the Internet through the home server, routed via the base stations and any intermediate devices in the network. The communication control unit is adapted to distribute the Internet connection to devices within the vehicle, allowing users to connect to the Internet whilst onboard the vehicle.
In order to connect to base stations provided by a mobile network operator, a Subscriber Identity Module (SIM) is required to authenticate the communication control unit with that mobile network operator. As network operators often do not have complete geographic coverage, and given that vehicles often travel between countries, it is generally desirable to be able to connect to a plurality of different network providers. This cannot generally be achieved using a single SIM. This problem is particularly acute where a vehicle crosses country boundaries, where available network operators may differ.
Further, many mobile telephone networks specify maximum data usage limits for particular SIMs, where exceeding the specified maximum data usage limit can result in an inability to send or receive further data, disrupting the provision of connectivity to users aboard the vehicle. Where a network operator allows data to be sent and received beyond the maximum data usage limit, heavy financial penalties are often levied. Again, this problem is particularly acute where a vehicle operates in different geographic areas, as using the data services of a national network operator with a SIM belonging to a network operator of a different country (i.e. “data roaming”) also often carries very heavy charges.
One solution is to carry a large number of SIMs aboard the vehicle. In this way, different SIMs can be used in different areas, thereby ensuring connectivity. It is further possible to cease using one SIM before exceeding a maximum data usage limit, and to begin using another of the SIMs. In order to use the additional SIMs, however, it is also necessary to carry sufficient numbers of modems, together with a large number of antenna, splitters and dividers required to properly support the modems. This results in increased cost, complexity and maintenance requirements.
The above problems are amplified when fleets of vehicles are considered. As each SIM is carried aboard the vehicle, even a modest fleet of vehicles would require an unwieldy number of SIMs, and associated equipment.
Another solution is to use connection means other than those provided by mobile network operators, such as WiFi or WiMax networks which may not require authentication using SIMs. However, while such networks may be beneficial for providing network connectivity in specified predefined areas, such as stations, such networks are not widely available for the routes along which vehicles generally travel. As such, they cannot be relied upon, alone, to provide connectivity to a vehicle.